Unit 8: Ecology Flashcards
Structural Hierarchy
every level of organization has a roll and is required for an organism to function (cell -> tissue -> organ -> organ system -> organism)
*any change to any level = changed function in the organism
Individual
single organism
Population
group of organisms in the same species
Community
collection of species in a region that interact with each other
Ecosystem
the species in an area and the abiotic environment they live in (climate, weather, pollution, etc)
Ecology
the study of how organisms interact with the living and nonliving components of the environment
Animal behaviors
All evolved animal behaviors exists because they are evolutionary adaptive (help organisms survive better + reproduce better)
- any animal behavior is typically more efficient (behavior changes to be more efficient)
Behavior
response to a stimulus (stimulus = internal or external change) - external can be environment or other organism
Innate Behavior
automatic/occur naturally in all members in a species (coded in the DNA)
- normally 100% necessary for survival and offers no flexibility
Learned Behaviors
ones an individual organism gains through experience by interacting with other organisms and environment
- ensures survival by allowing the organism to be reactive
Tactile communication
touch based communication, important for social groups of organisms
ex. honeybees dance with each other to give directions to flowers
this form of communication is limited by distance as organisms must be in direct contact with each other
Auditory Communication
sound based communication extremely important in wide variety of organisms
- lots of auditory communication is for mating
Visual Communication
uses signals that must be seen (posture, warning sign, facial expressions)
ex. poison dart frogs bright colors tell preds they are dangerous (some predators learn this by attempting to eat them)
Chemical Communication
use chemical signals called pheromones
ex. dogs mark territory when they pee (chemical communication can be used to communication about location of food, mark territory, warn others about danger)
Phototropism
the growth of a plant in response to light towards the light (INNATE BEHAVIOR)
- towards lights = max surface area for photosynthesis
- only plants with undamaged tips can do phototropism
the behavior works bc of signal transduction pathways and a hormone called Auxin
Auxin
the plant growth hormone that controls phototropism (ligand for the receptor)
- it moves to the darker side of the plant and causes those cells to bend and elongate bending whole plant towards the light
Transpiration
water loss through evaporation (in leaves)
- the leaves have holes (stromata) in the bottom to let CO2 in which is good but they also let water out which is bad
- turned into evolutionary compromise where stromata close during day to prevent sun from evaporating water and open at night to let CO2 in forth e dark reaction b/c it doesn’t need the sun for it (most glucose is produced at night)
Minimizes water loss
Rule of 10%
when one organism eats another, most energy is lost (only 10% of energy is actively transferred to new organism)
- creates food pyramids b/c less energy is available at top for pred so there need to be less of them and more prey/producers
Tropic level
an approximation of an organism’s energetic relationship (who eats it and what it eats) on a scale from 1 to 5
- can’t go higher then 5 b/c then there is so few energies there it isn’t worth is
PRODUCERS: bottom of the tropic level
- any organism that produces its own food (plants)
CONSUMERS:
- eat another organism for energy
- 4 levels (primary, secondary, tertiary, and quaternary) - higher level eats one below it
- Organisms can occupy different tropic levels
Decomposers/Detritovores
- when organisms die they are decomposed by decomposers (maggots, flies, etc)
- decomposers recycle the nutrients from the dead organisms into the soil where producers use those nutrients to grow and continue the cycle
*The ONLY way nutrients can be recycled (finite material) - in a food web, every organism is consumer by these
Metabolism
how an animal produces energy
Endothermy
metabolic strategy of generating heat using internal metabolism (warm blooded)
- maintain a steady body temperature ( only birds and mammals do this)
- more energy COST but more active in more environments
*as size decreases, metabolism increases b/c smaller endotherms have higher SA:V ratio so they lose energy more efficiently and must make up that energy faster
Ectothermy
metabolic strategy where body temp is dependent on heat transfer via the environment (cold blooded)
- they shut down when it is cold ( either hibernate or die b/c life span isn’t that long)
- only highly active when it’s warm
- includes amphibians, reptiles, fish, invertebrates
the water cycle
evaporation: liquid to gas
transpiration: (evaporation from plants)
condensation: gas to liquid
precipitation: liquid falls back to earth as liquid or solid
***humans can’t chemically change water cycle (we can only contaminant it)
The Carbon Cycle
carbon is NATURALLY in ecosystems + mostly in the atmosphere
problem: humans alter system by burning fossil fuels increasing Co2 in atmosphere + throwing ecosystem out of balance
The Nitrogen Cycle
nitrogen = LIMITING NUTRIENT (helps control populations b/c there’s a limited amount)
humans increase amount of nitrogen in cycle with fertilizers = changing ecosystem and evolutionary factors
The sulfur cycle
increasing amount of sulfur = acid rain as byproduct (messes with PH level and messes up ecosystem)
the phosphorus cycle
ONLY NUTRIENT THAT NEVER GOES INTO ATMOSPHERE (never a gas)
humans still increasing amount of phosphorus which is a limiting nutrient
Eutrophication
process of massive increases in limiting nutrients
ex: algae blooms use up all oxygen and deoxygenate the water = fish death
Density dependent factor
dependent on ho dense population is (more dense = the more the pop will be limited by factors)
ex. available resources available space, disease, competition, predation
Density independent factor
affect population equally regardless of how dense the population is
ex. weather, climate, pollution, natural disasters (normally environmental factors)
Logistic growth
growth once population stabilizes
- birth and death rate approximately equal and reaches carrying capacity
- density dependent factors are affecting this population now
Invasive species
a species that has been introduced accidentally or on purpose by humans (negative effects)
- invasive (non- native)
- access to plenty of resources
- no natural predators
- outcompetes native species for resources
Keystone species
through interaction with other species, helps maintain strength and biodiversity of whole ecosystem
- taking out a keystone species leads to ecosystem collapse
- decreased biodiversity = fragile ecosystem
K selected species
have few offspring and they take a lot of time to mature + develop. High parental investment + resources = most offspring reach maturity and live longer
- most Mammels are k selected
- pop size graph is increase till carrying capacity and slight curves
R selected species
MANY offspring and give little to no parental support or protection = many offspring die early but those that survive live longer
ex. sea turtles, mosquitos, plants/trees
Survivorship curve
what % of the population survives to/around max age
Type 1: most survive till they get old (death rate concentrated around end) - k selected species
Type 3: most die before the 1st 10% of life (death rate concentrated at beginning) - R selected
Type 2: even rate of dying through life (rabbits)
Symbiosis
many species live in close connection (helpful or hurtful they just live together)
- Mutualism - both species get something good
- Commensalism - one species gets benefit and other is unaffected ( does it exist)
- Parasitism - one species gets benefit, and one is physically harmed (a good parasite doesn’t kill it’s hort
Competition
limited reasources = must compete to get what they want
Interspecific: different species
Intraspecific: same species
can be passive or violent
Predation
when one thing eats another organism
follows boom bust pattern
Niche + Niche Partitioning
Niche = organisms’ particular role in ecosystems (environment + biological interactions)
Niche Partitioning = form of cooperation where similar organisms will occupy slightly different niches to decrease competition and live happily side by side
Ecological succession (primary and secondary)
the process of which an ecological community establishes OR is reestablishing itself and changing over time
ends in a CLIMAX COMMUNITY - stable community that can last for hundreds to thousands of years with high biodiversity
PRIMARY: take places after bare rock is exposed - w/o soil not many organisms survive take long time for pioneer species to create usable soil
SECONDARY: takes place when soil is already there (doesn’t need to make soil = faster reach to climax community)
- biodiversity increases at a faster rate than during primary
Species richness
of total unique species found in a community
Species diversity
more complex measurement that measures types of species and how evenly distributed species are ( more even spread = more diverse)
- biodiversity is good b/c it makes ecosystems strong and more resilient
Simpsons diversity index
ranges from 1 to 0 with 1 being super diverse to 0 being zero diversity
- takes into account richness and diversity
D = 1 - (Sum of n(n-1)/ N(N-1))
n= # of organisms of a PARTICULAR SPECIES
N = total # of organisms of all the species present
D = diversity
- add up all of the species together/ n(n - 1) for each species present
